/Engine/Source/Runtime/UMG/Public/Slate/SRetainerWidget.h
[EPaintRetainedContentResult](API\Runtime\UMG\Slate\SRetainerWidget\EPaintRetainedContentResult) PaintRetainedContentImpl ( const [FSlateInvalidationContext](API\Runtime\SlateCore\FastUpdate\FSlateInvalidationContext) & Context, const [FGeometry](API\Runtime\SlateCore\Layout\FGeometry) & AllottedGeometry, int32 LayerId )